Richards may make a cameo or two in season six, but will not be a regular, a source tells ET. Bravo is not commenting, and no official casting decisions have been announced for the next season.

Richards, 50, entered rehab for the fourth time in April after being arrested at the Beverly Hills Hotel for public intoxication. She recently left rehab to attend her daughter Brooke Brinson's beachside wedding in Mexico over Memorial Day weekend, but is now back.

"She is much better than she had been," the source tells ET about Richards' current state.

The troubled RHOBH star has been on the hit Bravo show since its first season in 2010. She has been open about her battle with alcohol addiction in the past.

"I’m an alcoholic," she said in January 2012 during a Real Housewives reunion show on Bravo. "I had so much guilt and shame for my behavior and what I did, and then I drank to cover the guilt and shame and make it go away. It is a vicious cycle."

In an interview with Dr. Phil in April, Richards talked about her latest setback. She was allegedly acting belligerent and refused to leave the restaurant inside the Beverly Hills Hotel prior to her arrest, and was charged with three misdemeanors -- one count of public intoxication, one count of resisting, obstructing, delaying a peace officer or EMT, and one count of battery upon a peace officer.

"I'm a very strong person and I have been sober," Richards told Dr. Phil. "I haven't been working a program. Living through a season on a show -- sometimes it's hard to just get through it. The fans are really hard on me."